Octopus Has A Brain In Its Head

Researchers Say The Animal Can Learn By Observation, A Very Sophisticated Accomplishment.

May 3, 1992|By Washington Post

WASHINGTON — The lowly octopus has a surprising intellectual ability, two brain researchers report: It can learn a task simply by watching another octopus do it.

Learning by observation, which might in this case be described as ''octopus see, octopus do,'' is considered a very advanced form of learning - one that is possible, some argue, only in a brain almost on the verge of conceptual thought.

Such mental capacities have been considered possible only in ''higher'' vertebrates, animals with backbones, such as mammals and not likely in the brains of invertebrates - like the octopus, which is classified with slugs and clams as a mollusk.

The research was conducted by Graziano Fiorito, a neurobiologist at the Stazione Zoologica in Naples, Italy, a major marine biological research center, and Pietro Scotto of the Universita di Reggio Calabria, also in Italy. Their report was published in last Friday's issue of the journal Science.

The octopus's ability to copy a model, the two wrote, is a skill well known in ''humans and (other) vertebrates, and it has been considered preliminary to conceptual thought; in this sense it appears related to the cognitive abilities of the animal learning system (of more advanced species).''

Their finding was based on a simple experiment involving Octopus vulgaris, the common octopus found throughout temperate and tropical seas. The largest ones measure 10 feet from the tip of the head to the end of the longest of the eight tentacles.

In the first stage of the experiment, an octopus was trained to swim to one of two differently colored balls placed in its tank. If the red ball was the ''right'' one in the experiment and the animal went to the white ball, it received a mild electric shock. If it went to the red ball, it could find a piece of fish hidden behind the ball.

Once the animal learned to go to the correct ball every time, an untrained octopus was placed in an adjacent tank so that it could watch the trained one. Octopuses have acute vision.

The scientists said the ''student'' observer watched the trained animal closely, its head and eyes tracking the action as the other jetted across the tank and wrapped its tentacles around the correct ball to get the fish.

The observer animals were allowed to see the trained ones perform four times, watching as they found food. Then the observers were isolated and given a pair of balls without reward or punishment.

The observers consistently chose the right balls right away, the scientists said, having learned much faster than the human-trained animals, which took an average of 16 trials to learn to go to the red balls consistently and 21 to go to the white ones.

In the first four trials of the observer animals, by contrast, they were right 86 percent of the time when a red ball was the ''right'' one and 70 percent of the time when a white ball was ''right.'' (Something about a red ball apparently was more attractive.)

Octopuses have a reputation among aquarium keepers as being curious, bright and easily trained.